The field of the invention is internal combustion engines and the invention relates more particularly to means for operating the exhaust and intake valves of internal combustion engines.
It is, of course, important that exhaust and intake valves of internal combustion engines move sufficiently away from the valve seat to permit the rapid entry and exhaust of gasses. Invariably, this is provided by a reciprocal longitudinal movement of a valve face away from a valve seat which, of course, provides an annular space through which the gasoline and air vapor enters in the case of an intake valve, and the burned gasses exhaust in the case of an exhaust valve.
The valve assemblies of internal combustion engines which drive the valve in a positive manner, not only during the opening of the valve but also during the closing of the valve, are referred to as desmodromic type valve assemblies. Such assemblies are advantageous particularly for engines operating at high rpms. When the valve must wait for the action of a valve spring to cause it to close, there is inherently an element of inertia which delays the closing of each valve. Various means have been proposed to provide this positive closing action and patents disclosing such action are as follows: U.S. Pat. No. 2,814,283; Italian Pat. No. 563,164; U.S. Pat. Nos. 1,408,781; 1,309,339; 1,238,263; 1,671,973, 1,185,516; 1,503,384; 1,541,081; 3,313,280; 3,254,637; and 3,610,218. Such structures, however, have invariably led to unacceptable wear and except for a few specialized racing engines, such valve assemblies have found no practical widespread use.